Input devices are commonplace in modern society and are typically used to convert human-induced analog inputs (e.g., touches, clicks, motions, touch gestures, button presses, scroll wheel rotations, etc.) made in conjunction with an input device into digital signals for computer processing. An input device can include any device that can provide data and control signals to a computing system. Some non-limiting examples of input devices include computer mice, keyboards, virtual reality and/or augmented reality controllers, touch pads, remote controls, gaming controllers, joysticks, trackballs, and the like. Some non-limiting examples of computing systems include desktops, laptops, tablets and “phablet” computers, smart phones, personal digital assistants, wearable devices (e.g., smart watches, glasses), virtual reality (VR) and/or augmented reality (AR) systems, and the like.
Computer mice, in particular, have undergone significant improvements in functionality, accuracy, ergonomics, and versatility. Earlier designs, including the “mechanical mouse,” used a rubber ball coupled to two freely rotating rollers situated 90 degrees from one another to roll along an underlying surface. The first roller detects forward-backward motion of the mouse and the second roller detects left-right motion, with each roller sharing the same shaft as a corresponding encoder wheel with slotted edges that interrupt infra-red light beams generate electrical pulses that can be translated to wheel movement. Mechanical mice were notorious for picking up dirt, unpredictable tracking, and needing frequent disassembly and cleaning.
Contemporary mice may include surface-independent optical mice using optoelectronic sensors to compare successive images of the underlying surface on which the computer mouse operates to interpret movement. Technological improvements have allowed optical mice to be used along varied types of surfaces (e.g., table tops, paper, glass, etc.) without the need for a special mouse pad. Optical mice typically employ light-emitting diodes (LEDs) and/or laser (e.g. coherent) light and an imaging array of photodiodes to detect movement relative to the underlying surface, which has proven to be much more reliant, robust, and accurate than their mechanical counterparts. Despite these improvements, broader-use designs are needed.